A conventional wheelchair is bulky and not convenient for folding and storage, especially, the folded wheelchair is not convenient to be put into the trunk of vehicles.
A conventional wheelchair generally includes a frame with wheels, a seat and a backrest. The frame includes two separated side parts and a folding device is pivotably connected between the two side parts so as to expand or fold the two side parts. Each side part has a top bar and a bottom bar which is parallel to the top bar. The folding device includes two support rods which are respectively and pivotably connected to the first end and the second end of the bottom bar, wherein the second end is located remote from the first end and is connected to the seat. The two support bars are pivotable at a pivot at a mediate portion thereof. At least two connection members are respectively connected to the top bars on the two side parts and each connection member has a through hole which is axially defined in the top bar. At least two links are provided and each link has a first pivotal end and a second pivotal end, wherein the two respective first pivotal ends are pivotably connected to the support rods and the two respective second pivotal ends are located in alignment with the through holes, and two shafts extend through the second ends and the through holes.
Another conventional wheelchair generally includes two separated side parts and a folding device is pivotably connected between the two side parts. Each of the side parts has a bottom bar and a top bar which is parallel to the bottom bar. Two lugs extend from the bottom bar and extend toward the other side part. At least one support portion extends from the top bar and toward the other side part. The folding device includes two pivotal rods which are parallel to the bottom bars of the two side parts and two ends of each of the two pivotal rods are located corresponding to the lugs corresponding thereto. At least two rotatable rods are provided and each has one end fixed to the pivotal rod corresponding thereto. A shaft is pivotably between two respective mediate portions of the two rotatable rods and the axis of the shaft is parallel to the pivotal shaft of the two pivotal rods so that the two rotatable rods are pivotable about the shaft. Two support rods are respectively and perpendicularly connected to the other two respective ends of the rotatable rods. The two support rods are parallel to the two pivotal rods. Therefore, the two support rods are moved between an expansion position and a folding position when the two rotatable rods are pivoted. When the wheelchair is expanded, the two support rods are connected to the side parts and supported by the support portions.
However, the support is insufficient when the wheelchair is expanded and so that when the user use the wheelchair, the wheelchair might collapse suddenly and the safety problem is the main concern for the conventional folding device.
The present invention intends to provide a folding device for wheelchair and the folding device of the present invention improves the shortcoming of the conventional folding device.